The present invention relates to the field of pressurizing devices, and in particular to a device for pressurizing a first tank with a cryogenic fluid contained in a second tank and introduced into the first tank via a pressurizing circuit after being heated in a heat exchanger of said pressurizing circuit.
Pressurizing devices of this type are used in particular in the field of propulsion, and more particularly in systems for feeding propellants to reaction engines, and in particular to rocket engines. Thus, by way of example, one such pressurization device is used in the main cryogenic stage of Ariane 5 space launchers in order to pressurize the liquid oxygen tank for feeding the Vulcain main engine.
A drawback of prior art pressurizing devices, and in particular that used in the main pressurizing stage, is that the second tank itself needs to be pressurized with a gas contained in other tanks under pressure. Thus, in the main cryogenic stage, the supercritical helium tank of the liquid helium subsystem used for pressurizing the liquid oxygen tank is itself pressurized with gaseous helium coming from a gaseous helium tank forming a high pressure reservoir. This high pressure reservoir contains supercritical helium at a pressure close to 400 bar and at ambient temperature. Three-quarters of the helium contained in the high pressure reservoir is used for pressurizing the supercritical helium tank of the liquid helium subsystem, with the remainder being supplied to the hydrogen and oxygen feed valves of the pogo corrector system, and to the engine flushing and engine control solenoid valve units. In order to bring the pressure that exists in the high pressure reservoir down to a utilization pressure of less than 100 bar, this reservoir also requires an inflation and expansion plate. The combined mass of the high pressure reservoir and of the inflation and expansion plate significantly penalizes the payload of the launcher. In addition, the inflation and expansion plate constitutes an element that is mechanically complex, and which can have a negative effect on the reliability of the launcher.